Islamic seminaries, or madrasas, have received a lot of attention from academics around the world. For instance, Zareena Grewal's book, "Islam is a Foreign Country," examined how American youth travel the world to study Islam.

The role of full-time, Islamic K-12 schools offering secular education, however, has not been explored in much depth. They are a growing sector of American society, but they remain grossly misunderstood.

To shed light on them, we surveyed more than 230 Islamic schools in the United States and interviewed more than 25 principals and board members. We included both immigrant, community-based schools and African-American-founded schools.

Most Islamic schools resemble other religious schools. Like Catholic and Jewish schools, they provide religious education. This makes up as little as 10 percent to as much as 25 percent of their curriculum. The rest is devoted to other subjects.

Muslim-American schools are evolving in relation to other mainstream American institutions, borrowing from their best practices and norms. While there is often direct collaboration when it comes to issues like interfaith dialogue, in other cases the influence of mainstream or secular institutions is subtler.

For instance, all Muslim-American institutions have adopted the nonprofit form, which allows them to benefit from income tax deductions. This also serves as a way to legitimize their missions and gain credibility, both within and outside of the communities in which they exist.

We also looked at the role of philanthropy — perhaps the most American of values given that more Americans give money to charities than vote. Philanthropy plays a key role in the founding of the schools. In the long run, the role of philanthropy often diminishes and other sources of revenue play a bigger role. For instance, revenue from fees takes an upper hand in most cases. Philanthropy remains a close second as a source of revenue.

One of our most counterintuitive findings was that Islamic schools have been instrumental in helping their students develop a greater sense of civic awareness and, hence, become better Americans.

Islamic schools help produce community leaders. They have produced a bulk of the civic leaders in the Muslim-American community. This should not come as a surprise, given that Muslim institutions in the U.S. generally encourage their members to be active members of the local, national and international civil society.

This messaging is reinforced in many ways, including through service-learning activities, interaction with local communities and the formation of education boards. Amaney Jamal with Princeton University has shown that participation in mosque activities is directly correlated with greater political and civic engagement. This also ties in with work by Robert Wuthnow of Princeton and Robert Putnam of Harvard University showing that social capital is higher among those who participate in religious institutions than among those who don't.

All Islamic schools transfer knowledge, culture and traditions, but they have different values and norms when it comes to what it means to offer an Islamic education. Our interviews revealed a continuum of Islamic school identity and attitudes regarding how visible the Islamic element of the school should be. There seems to be a vast divergence in terms of how much each school wants to be perceived as Islamic.

While all the school principals agree that the values of honesty, integrity, collaboration, accountability and modesty should be imparted, they diverge on the issue of branding these values as being particular to Islamic institutions.

Some see their schools as regular institutions that follow these Islamic values. As other scholars have pointed out, Islamic schools foster the values that are at the root of any educational endeavor: discipline, teaching children critical thinking and fostering character development.

Most Muslim-Americans are middle-class and mainstream, as a recent Pew Research Center study pointed out. This translates into an education system that promotes inclusion, tolerance and mainstreaming of voices.

Sabith Khan is an assistant professor in the California Lutheran University School of Management. Shariq Siddiqui is the executive director of the Association for Research on Nonprofit and Voluntary Action in Indianapolis. They are the authors of "Islamic Education in the United States and the Evolution of Muslim Nonprofit Institutions," which will be released this month.